626 VIBRIO 



Vibrio danubicus. — Isolated by Heider (1893) from the Danube canal. Resembles 

 the cholera vibrio closely, but can be differentiated by serological reactions. 



Vibrio helcogenes. — Isolated by Fischer (1893) from the diarrhceal f feces of a woman. 

 Some of the mice inoculated subcutaneously developed ulcers of the skin ; hence the name. 



The Massauah vibrio was isolated by Pasquale (1891) from the faeces of a patient who 

 was probably not suffering from cholera. Resembles the cholera vibrio closely, but has 

 four peritrichate flagella ; it is therefore not a true Vibrio. The Ghinda vibrio was isolated 

 by Pasquale from water ; it was regarded as a true cholera vibrio, but has since been 

 shown to be distinguished from it by its immunity reactions. 



The Nasik vibrio differs in several respects from V. cholerce. It is less like a comma 

 and is short and rather fat : arranged singly, and with great regularity ; filamentous 

 forms are common. The colonies on agar are more opaque than those of cholera. Infun- 

 dibuliform liquefaction occurs in gelatin, later stratiform ; the liquefied gelatin is uniformly 

 turbid and contains no flocculi. No growth under anaerobic conditions. Acid in glucose 

 only; L.M. purple and clotted; indole — ; nitrate reduction^; NH3-)-; HjS — ; 

 Catalase-[-+ ; M.B. reduction — ; cholera-red reaction — ; yS-haemolysis in horse blood 

 agar plates in 4 days. Cafe-au-lait growth on potato. Broth cultures are very toxic 

 to rabbits on intravenous injection (KoUe and Schiirmann 1912). 



Vibrio fetus. — This organism, on account of its special characteristics, must be 

 considered separately. It was first isolated and described by M'Fadyean and 

 Stockman in 1913 (see Report 1913), who found it in the uterine exudate of aborting 

 sheep. Smith (1918) cultivated the same organism in America from the foatuses 

 of aborting cows (see Chapter 75) ; he named it F. fetus (Smith and Taylor 

 1919). In young cultures it is generally shaped like a comma, but later it assumes 

 a spirillar appearance. It is questionable whether this organism should be classified 

 as a Vibrio or as a Spirillum ; its characters partake of both groups. But since 

 Smith has placed it with the vibrios, since it has a single polar flagellum, and since 

 it is Gram-negative, it is perhaps best to regard it as belonging to the Vibrio group. 



Morphologically, the smallest forms appear as minute, slender, s-shaped threads ; the 

 longest forms may stretch nearly across the field of the microscope. In length it is 1-5 

 to 5 /i or more, and in breadth about 0-2 to 0-3 fi. A single organism shows one or two 

 spirals ; the length of each spiral is about 2 fi, and the amplitude about 0-5 /x. In the long 

 forms the spirals are drawn out, so that their length is far greater than their breadth. 

 The short forms are sharply curved ; the spirals often show an obtuse-angled curve. In 

 young cultures the vibrios are actively motile by a single polar flagellum ; in cultures 

 a week old very few are motile. The organism is best stained with alkaline methylene 

 blue, the staining being prolonged over-night. It is Gram-negative. In old cultures 

 many of the organisms show granular degeneration. 



For growth in artificial media, a reduced oxygen pressure is required. When first 

 isolated, it will not grow on agar without the addition of blood or some other animal fluid. 

 The growth is very delicate, and occurs at the edges of the slope between the agar and the 

 glass ; subsequently it spreads round the convexity of the agar. After some months of 

 cultivation in the laboratory, a thin surface growth may be obtained. Growth in fluid 

 media, even in blood broth, does not occur till the strain has become thoroughly accustomed 

 to saprophytic conditions. There is no growth in gelatin, milk or potato. Sugars are 

 not fermented, and there is no production of indole. In cultures, it lives for 2 to 20 weeks 

 at room temperature, but dies rapidly in the ice-chest. Dried on threads, it lives for 

 less than 3 hours. It is killed by 56° C. in 5 minutes. The optimum temperature for 

 growth is 37° C. Antigenically it appears by agglutination to be homogeneous (Smith 

 and Taylor 1919). It is non-pathogenic to laboratory animals. Under natural conditions 

 it gives rise apparently to abortion in cattle and sheep. Experimental inoculation of pure 



